In many instances, the information to be conveyed to a user does not conveniently fit within the constraints of the size of the available display of a device. This can be especially problematic, where the size of the display is relatively small. The size of the display is often dictated by the size of the device in which the display is used.
For many handheld type devices, like wireless communication devices, there is a trend toward smaller devices. Smaller devices are easier to carry on one's self, where the smaller the device, the greater the number of options for the location where the user can store the device (i.e a pocket, a belt clip, a small hand bag, etc.). However, as the device size decreases, so does the surface area of the device, where the components are located, which the user uses to interface with the device. For example, displays, microphones, speakers and keypads are typically located at various positions around the external surface of the device, where they are conveniently accessible by the user.
The amount of surface area of the device can be increased, by allowing the device to fold open during usage. The device is allowed to fold closed when the device is ready to be stored or the device is to be used in a more limited fashion, where more limited user interaction may only be required. However, when it comes to displays, there seems to never be enough room to display all of the information, that one would want to display on the screen.
Many devices use scrolling to accommodate the selective displaying of the most relevant information, or selectively between equally relevant information that will not fit on the screen at one time. Generally, the scrolling is controlled by the depression of one of two or four buttons, which each controls the scrolling of the information displayed on the screen in one of at least a couple of directions. Where the information extends beyond the size of the screen in a single dimension, two buttons are usually sufficient to move the information being displayed either up and down, or left and right. Where the information extends beyond the size of the screen in two dimensions, four buttons are often used to pan the display, either up, down, left or right. However, where buttons have largely been used to control scrolling in many devices, other alternative techniques have also been developed.
At least one prior patent, Singh et al., U.S. Pat. No. 6,400,376, uses the relative movement of the device to control the direction in which the display pans. A further prior patent, Motosyuku et al., U.S. Pat. No. 5,602,566, controls the direction and speed of the scrolling, by detecting the direction and the degree of the tilt of a device. However, in each instance the amount of information being conveyed to the user by the display at any one time is limited by the amount of information that can be displayed on the screen at the same time.
Consequently, in order to display a greater amount of information to the user, than the amount of information, which can be displayed on the display at any one time, without increasing the screen size, there is a need for a method and apparatus for virtually expanding the display.
Most users' eyes experience what is commonly referred to as “persistence of vision”. Others, including psychologists, have referred to this effect as “positive after images”. In essence, there is a delay between the time that a changing image will blur between one image and the next. The delay is often associated with the contrast or brightness of different elements from each of the images. For example if one stares at a bright light, an after image of the light will remain for a period of time, even after one looks away from the bright light, or closes one's eyes. Additionally, the brain can at times perceive the movement between two related still images, that are viewed sequentially. In this way, sequentially viewed still images, observed in sequence at a sufficiently fast rate, like a motion picture, will give the appearance of smooth continuous movement.
Early experiments associated with “persistence of vision” suggest that a minimum of 10 separate frames per second is necessary to give the illusion of movement. However at 10 frames per second there is substantial flicker. A flicker rate on the order of at least 50 frames per second is necessary for the flicker of the image not to be obvious. In some instances, a frame can include a repeated frame or an image that has been flashed multiple times. In this instance, the multiple flashings count as multiple frames within the 50 frames per second. In effect requiring that the image displayed on the screen be updated at a reduced rate. In the early days of motion pictures, this effect was created by using a multiple bladed shutter.
The present inventor has recognized that if the amount of panning on the screen could coincide with the amount or degree of movement of the device, by moving the device back and forth, and if a sufficient frame rate could be maintained, using the “persistence of vision” and “positive after images” associated with the eyes, an apparent larger image, which exceeds the size of the display can be realized. The back and forth movement of the device, and the correspondingly panned image, periodically refreshes the respective portion of the image across an area that has a size, which is larger than the size of the display. In this way an apparent larger screen image can be realized. In addition to a back and forth movement a circular movement could also be used to create image effects that exceed the screen size in more than a single dimension.